This disclosure relates generally to image production in electrophotographic systems and, more particularly to systems and methods for image gloss control.
A conventional apparatus for forming a image using an electrophotographic system generally uses a system in which an image formed of a toner is carried on an image carrying member, such as a photoreceptor drum and an intermediate transfer belt, and the image is transferred and fixed to a recording medium such as paper.
This kind of image forming apparatus may have, as a fixing device for rapidly fixing the toner image to the recording medium, a fixing unit, the recording medium containing the toner image being nip-transported under heating and pressing between a pair of fixing rolls, which are rotated in contact with each other. Such systems are generally referred to as fusers because they fuse the toner image to the recording medium.
Many documents produced by such systems, and, especially color printers, have a need for a uniform, high gloss. However, many fuser issues can lead to non-uniform gloss or a gradual change in gloss as the fuser ages. Examples of fuser roll induced gloss defects include edge wear, oil streaks, and air knife streaks such as from cool rings (due to non-uniform cooling of the fuser roll or recording medium after fusing) and random wavy gloss and gloss reduction as material accumulates on the roll that contacts the image. Post fuser temperature disparities also alter the image gloss. Post fuser gloss defects include belt hole artifacts from the post fuser belt transport.
Many of the roll-induced gloss defects improve when the fuser roll is replaced. However, if the gloss defects could be cured by a post-fuser heating process, useful fuser roll lifetimes could be extended by at least a factor of two and likely more.